Just curious about the budget. It authorizes the executive branch to spend money but does it require it? The part that is discretionary, could ‘t the president just not spend it?
No, if Congress appropriates the money the Executive Branch MUST spend it.
Presidents used to have this power before Nixon. He was trying to get control of profligate spending and held back large sums, which he returned to the Treasury at year end. This got the Democrats bent all out of shape so they passed the Impoundment Control Act of 1974, which required him to get approval from Congress to impound funds. (they had taken advantage of Nixon’s cratering popularity in Watergate and accused him of “abusing his power”)
Nixon for whatever reason signed it into law three weeks before he left office. Subsequent Supreme Court interpretations have stripped even more of this power from the POTUS.
Yet another reason this mess is as far out of whack as it is today.